1. Field of the Invention
This invention relates generally to dispensers and more particularly to powdered detergent dispensers for washing machines.
2. Description of the Prior Art
Automated washing machines used in commercial applications have typically used powdered detergents and consume large amounts of such detergents in the course of their daily operations. It is advantageous from both time and cost standpoints for the operators of such machines to only periodically supply the machine with powdered detergent, say for example, only once during a working day. Accordingly, commercial washing machines have typically been designed for use with auxiliary detergent dispensers capable of holding sizable amounts of powdered detergent and operable to periodically convert the detergent to concentrated detergent solution as needed for use by the washing machine Such washing machines are generally configured to embody at least one wash tank or reservoir for maintaining a supply of detergent solution for use by the washing machine. The washing machine repeatedly uses the detergent solution within the reservoir for a period of time, such as one day, until it is replaced by a new solution. During normal usage, a certain amount of the detergent solution is drained off, for example with food particles and grease in dishwashing applications, to keep the remaining solution as clean as possible. Water is then added to the reservoir to maintain the proper level. This reduces the concentration of the solution in the reservoir. In order to keep the detergent solution in the reservoir at the proper concentration, concentrated detergent solution is periodically added to the reservoir by the auxiliary detergent dispenser.
Use of an automated detergent dispenser system eliminates the need of constant operator attention to the status of the reservoir solution and provides greater accuracy in maintaining the actual concentration level of the detergent solution within the reservoir.
Many automatic auxiliary detergent dispensing systems have appeared in the prior art. Such dispensers can be generally charactertized by: (1) those dispensing systems which are remotely located (usually in a different physical location) from the washing machine proper, and (2) those dispensing systems which are configured for mounting to or directly adjacent the washing machine proper. The remotely located dispensers are typically configured for handling large 30 to 50 gallon shipping containers of powdered detergent and for directly converting the detergent within these containers into a concentrated detergent solution. Dispensers of this type have selfcontained reservoirs for maintaining a supply of the concentrated solution produced, and a pump for transferring on demand the concentrated solution from the dispenser reservoir to the wash tank of the washing machine proper. In general, such apparatus requires considerable space oftentimes not available on the premises where the washing machine is located, are somewhat cumbersome to use since large shipping containers must be handled by the operator, and do not generally lend themselves to efficient use with smaller or occasionally used washing machines. Dispensers within the second-listed catagory, and to which this invention pertains are much smaller than their remotely located counterparts, and are sized to hold relatively smaller amounts of detergent, thus enabling ease of loading by a wide range of machine operators. Such dispensers can be readily mounted in out-of-the-way positions directly to the washing machine proper, typically on top of the washing machine, and are generally more versatile in their application then the remotely located dispensers. These dispensers are generally loaded from the top and directly supply the adjacent washing machine reservoir with their produced detergent solution by gravity feed, thus eliminating the need and expense for pump means and providing an added dimension of reliability.
Most prior art dispensers of the type which are connected directly to the washing machine have been configured for mounting on top of the machine or within the chassis of the machine generally overlying the wash tank or reservoir. In such dispensers, it has been commonplace to totally immerse the detergent powder in water to form a saturated solution or slurry. A stand pipe usually located in the middle of the dispenser holding tank or pot, maintains a constant water level within the dispenser. When the washing machine requires additional detergent solution for the wash tank, a controller opens a solenoid valve which causes water to flow into the dispenser pot. The added water causes a portion of the saturated solution in the pot to flow into the stand pipe and to fall directly into the underlying wash tank. When the detergent concentration level in the wash tank attains a predetermined level of concentration, the controller shuts off the water supply to the dispenser by closing the solenoid valve. A drawback of the above-described device is that since the detergent is always saturated, the concentration level of the detergent solution produced by the dispenser over a period of time will vary as the detergent solution within the dispenser pot is diluted. Further, such apparatus cannot be used with powdered detergents containing active chlorine, since most of the chlorine contained in such detergents is lost through decomposition once the detergent is wetted.
Such top mounted dispensers are also dangerous to an operator responsible for loading powdered detergent into the dispenser pot. Due to the position of the dispenser over the washing machine, the heat from the machine raises the solution temperature within the dispenser pot to near the wash temperature (i.e. approximately 150.degree. to 160.degree. Fahrenheit). When caustic containing compounds are rapidly added to the dispenser pot, the heat of hydration may cause the solution to boil, presenting a hazardous situation to the operator. This hazard is increased by the fact that due to the top mounting of such dispensers, the operator is required to load such apparatus at or above eye level, thus increasing the danger of caustic splash or spray to his face and eyes.
In an effort to avoid many of the above problems, some dispensers have been configured so as to support a mass of powdered detergent within a large inverted container over a screen mesh and so as to form a detergent solution by wetting the powdered detergent by means of a spray directed through the screen. Such dispenser construction has been successfully used with the large remotely located type of dispensers which employ an underlying reservoir and a pump for forwarding the prepared solution to the washing machine. While some of these principles have been applied to dispensers of the type mounted on or adjacent to the washing machine, none of the prior art dispensers of this type offer that combination of features which solve all of the above problems in a manner that is completely non-hazardous to the attending operator. One example, of such a prior art dispenser theoretically mountable to a washing machine, supports a mass of powdered detergent on a conical screen suspended within a top loading housing. The carried detergent is dissolved by means of a spray of water directed against the convexly shaped surface area of the screen.
While this device solves many of the prior art problems associated with such machine mounted dispensers, its design enables excessive penetration of the spray into the detergent, causing extensive hydration thereof, making this device unattractive for use with active chlorine containing detergents. Further, this dispenser does not include any safety features for protecting an operator loading the dispenser.
The present invention overcomes the above-mentioned shortcomings of the prior art powdered detergent dispensers of the type configured for mounting on or adjacent the washing machine. The dispenser apparatus of the present invention provides a simple non-hazardous and reliable technique for producing highly concentrated detergent solution for use on a demand basis by an attached or adjacent washing machine, produces such solutions which are of substantially uniform composition and concentration throughout the conversion of the entire contents within the detergent dispenser, and minimizes waste due to unusable residues remaining in the dispensing container. The configuration of the dispenser container enables the dispenser to be mounted on the side wall of the washing machine at a level so as to enable ease of operator loading and at a height which does not present a direct hazard to the face and eyes of the operator. Further, automatic safety features of the invention disable operation of the dispenser spray apparatus whenever the loading port is opened by an operator.